/*!
 * Date picker for pickadate.js v3.5.6
 * http://amsul.github.io/pickadate.js/date.htm
 */
define(function (require, exports, module) {
    var $ = require('jquery'), Picker = require('picker');
    /**
     * Globals and constants
     */
    var DAYS_IN_WEEK = 7,
        WEEKS_IN_CALENDAR = 6,
        _ = Picker._

    /**
     * The date picker constructor
     */
    function DatePicker(picker, settings) {

        var calendar = this,
            element = picker.$node[0],
            elementValue = element.value,
            elementDataValue = picker.$node.data('value'),
            valueString = elementDataValue || elementValue,
            formatString = elementDataValue ? settings.formatSubmit : settings.format,
            isRTL = function () {

                return element.currentStyle ?

                    // For IE.
                    element.currentStyle.direction == 'rtl' :

                    // For normal browsers.
                    getComputedStyle(picker.$root[0]).direction == 'rtl'
            }

        calendar.settings = settings
        calendar.$node = picker.$node

        // The queue of methods that will be used to build item objects.
        calendar.queue = {
            min: 'measure create',
            max: 'measure create',
            now: 'now create',
            select: 'parse create validate',
            highlight: 'parse navigate create validate',
            view: 'parse create validate viewset',
            disable: 'deactivate',
            enable: 'activate'
        }

        // The component's item object.
        calendar.item = {}

        calendar.item.clear = null
        calendar.item.disable = (settings.disable || []).slice(0)
        calendar.item.enable = -(function (collectionDisabled) {
            return collectionDisabled[0] === true ? collectionDisabled.shift() : -1
        })(calendar.item.disable)

        calendar.
            set('min', settings.min).
            set('max', settings.max).
            set('now')

        // When there’s a value, set the `select`, which in turn
        // also sets the `highlight` and `view`.
        if (valueString) {
            calendar.set('select', valueString, {
                format: formatString,
                defaultValue: true
            })
        }

            // If there’s no value, default to highlighting “today”.
        else {
            calendar.
                set('select', null).
                set('highlight', calendar.item.now)
        }


        // The keycode to movement mapping.
        calendar.key = {
            40: 7, // Down
            38: -7, // Up
            39: function () { return isRTL() ? -1 : 1 }, // Right
            37: function () { return isRTL() ? 1 : -1 }, // Left
            go: function (timeChange) {
                var highlightedObject = calendar.item.highlight,
                    targetDate = new Date(highlightedObject.year, highlightedObject.month, highlightedObject.date + timeChange)
                calendar.set(
                    'highlight',
                    targetDate,
                    { interval: timeChange }
                )
                this.render()
            }
        }


        // Bind some picker events.
        picker.
            on('render', function () {
                picker.$root.find('.' + settings.klass.selectMonth).on('change', function () {
                    var value = this.value
                    if (value) {
                        picker.set('highlight', [picker.get('view').year, value, picker.get('highlight').date])
                        picker.$root.find('.' + settings.klass.selectMonth).trigger('focus')
                    }
                })
                picker.$root.find('.' + settings.klass.selectYear).on('change', function () {
                    var value = this.value
                    if (value) {
                        picker.set('highlight', [value, picker.get('view').month, picker.get('highlight').date])
                        picker.$root.find('.' + settings.klass.selectYear).trigger('focus')
                    }
                })
            }, 1).
            on('open', function () {
                var includeToday = ''
                if (calendar.disabled(calendar.get('now'))) {
                    includeToday = ':not(.' + settings.klass.buttonToday + ')'
                }
                picker.$root.find('button' + includeToday + ', select').attr('disabled', false)
            }, 1).
            on('close', function () {
                picker.$root.find('button, select').attr('disabled', true)
            }, 1)

    } //DatePicker

    /**
     * Set a datepicker item object.
     */
    DatePicker.prototype.set = function (type, value, options) {

        var calendar = this,
            calendarItem = calendar.item

        // If the value is `null` just set it immediately.
        if (value === null) {
            if (type == 'clear') type = 'select'
            calendarItem[type] = value
            return calendar
        }

        // Otherwise go through the queue of methods, and invoke the functions.
        // Update this as the time unit, and set the final value as this item.
        // * In the case of `enable`, keep the queue but set `disable` instead.
        //   And in the case of `flip`, keep the queue but set `enable` instead.
        calendarItem[(type == 'enable' ? 'disable' : type == 'flip' ? 'enable' : type)] = calendar.queue[type].split(' ').map(function (method) {
            value = calendar[method](type, value, options)
            return value
        }).pop()

        // Check if we need to cascade through more updates.
        if (type == 'select') {
            calendar.set('highlight', calendarItem.select, options)
        }
        else if (type == 'highlight') {
            calendar.set('view', calendarItem.highlight, options)
        }
        else if (type.match(/^(flip|min|max|disable|enable)$/)) {
            if (calendarItem.select && calendar.disabled(calendarItem.select)) {
                calendar.set('select', calendarItem.select, options)
            }
            if (calendarItem.highlight && calendar.disabled(calendarItem.highlight)) {
                calendar.set('highlight', calendarItem.highlight, options)
            }
        }

        return calendar
    } //DatePicker.prototype.set


    /**
     * Get a datepicker item object.
     */
    DatePicker.prototype.get = function (type) {
        return this.item[type]
    } //DatePicker.prototype.get


    /**
     * Create a picker date object.
     */
    DatePicker.prototype.create = function (type, value, options) {

        var isInfiniteValue,
            calendar = this

        // If there’s no value, use the type as the value.
        value = value === undefined ? type : value


        // If it’s infinity, update the value.
        if (value == -Infinity || value == Infinity) {
            isInfiniteValue = value
        }

            // If it’s an object, use the native date object.
        else if ($.isPlainObject(value) && _.isInteger(value.pick)) {
            value = value.obj
        }

            // If it’s an array, convert it into a date and make sure
            // that it’s a valid date – otherwise default to today.
        else if ($.isArray(value)) {
            value = new Date(value[0], value[1], value[2])
            value = _.isDate(value) ? value : calendar.create().obj
        }

            // If it’s a number or date object, make a normalized date.
        else if (_.isInteger(value) || _.isDate(value)) {
            value = calendar.normalize(new Date(value), options)
        }

            // If it’s a literal true or any other case, set it to now.
        else /*if ( value === true )*/ {
            value = calendar.now(type, value, options)
        }

        // Return the compiled object.
        return {
            year: isInfiniteValue || value.getFullYear(),
            month: isInfiniteValue || value.getMonth(),
            date: isInfiniteValue || value.getDate(),
            day: isInfiniteValue || value.getDay(),
            obj: isInfiniteValue || value,
            pick: isInfiniteValue || value.getTime()
        }
    } //DatePicker.prototype.create


    /**
     * Create a range limit object using an array, date object,
     * literal “true”, or integer relative to another time.
     */
    DatePicker.prototype.createRange = function (from, to) {

        var calendar = this,
            createDate = function (date) {
                if (date === true || $.isArray(date) || _.isDate(date)) {
                    return calendar.create(date)
                }
                return date
            }

        // Create objects if possible.
        if (!_.isInteger(from)) {
            from = createDate(from)
        }
        if (!_.isInteger(to)) {
            to = createDate(to)
        }

        // Create relative dates.
        if (_.isInteger(from) && $.isPlainObject(to)) {
            from = [to.year, to.month, to.date + from];
        }
        else if (_.isInteger(to) && $.isPlainObject(from)) {
            to = [from.year, from.month, from.date + to];
        }

        return {
            from: createDate(from),
            to: createDate(to)
        }
    } //DatePicker.prototype.createRange


    /**
     * Check if a date unit falls within a date range object.
     */
    DatePicker.prototype.withinRange = function (range, dateUnit) {
        range = this.createRange(range.from, range.to)
        return dateUnit.pick >= range.from.pick && dateUnit.pick <= range.to.pick
    }


    /**
     * Check if two date range objects overlap.
     */
    DatePicker.prototype.overlapRanges = function (one, two) {

        var calendar = this

        // Convert the ranges into comparable dates.
        one = calendar.createRange(one.from, one.to)
        two = calendar.createRange(two.from, two.to)

        return calendar.withinRange(one, two.from) || calendar.withinRange(one, two.to) ||
            calendar.withinRange(two, one.from) || calendar.withinRange(two, one.to)
    }


    /**
     * Get the date today.
     */
    DatePicker.prototype.now = function (type, value, options) {
        value = new Date()
        if (options && options.rel) {
            value.setDate(value.getDate() + options.rel)
        }
        return this.normalize(value, options)
    }


    /**
     * Navigate to next/prev month.
     */
    DatePicker.prototype.navigate = function (type, value, options) {

        var targetDateObject,
            targetYear,
            targetMonth,
            targetDate,
            isTargetArray = $.isArray(value),
            isTargetObject = $.isPlainObject(value),
            viewsetObject = this.item.view/*,
        safety = 100*/


        if (isTargetArray || isTargetObject) {

            if (isTargetObject) {
                targetYear = value.year
                targetMonth = value.month
                targetDate = value.date
            }
            else {
                targetYear = +value[0]
                targetMonth = +value[1]
                targetDate = +value[2]
            }

            // If we’re navigating months but the view is in a different
            // month, navigate to the view’s year and month.
            if (options && options.nav && viewsetObject && viewsetObject.month !== targetMonth) {
                targetYear = viewsetObject.year
                targetMonth = viewsetObject.month
            }

            // Figure out the expected target year and month.
            targetDateObject = new Date(targetYear, targetMonth + (options && options.nav ? options.nav : 0), 1)
            targetYear = targetDateObject.getFullYear()
            targetMonth = targetDateObject.getMonth()

            // If the month we’re going to doesn’t have enough days,
            // keep decreasing the date until we reach the month’s last date.
            while ( /*safety &&*/ new Date(targetYear, targetMonth, targetDate).getMonth() !== targetMonth) {
                targetDate -= 1
                /*safety -= 1
                if ( !safety ) {
                    throw 'Fell into an infinite loop while navigating to ' + new Date( targetYear, targetMonth, targetDate ) + '.'
                }*/
            }

            value = [targetYear, targetMonth, targetDate]
        }

        return value
    } //DatePicker.prototype.navigate


    /**
     * Normalize a date by setting the hours to midnight.
     */
    DatePicker.prototype.normalize = function (value/*, options*/) {
        value.setHours(0, 0, 0, 0)
        return value
    }


    /**
     * Measure the range of dates.
     */
    DatePicker.prototype.measure = function (type, value/*, options*/) {

        var calendar = this

        // If it’s anything false-y, remove the limits.
        if (!value) {
            value = type == 'min' ? -Infinity : Infinity
        }

            // If it’s a string, parse it.
        else if (typeof value == 'string') {
            value = calendar.parse(type, value)
        }

            // If it's an integer, get a date relative to today.
        else if (_.isInteger(value)) {
            value = calendar.now(type, value, { rel: value })
        }

        return value
    } ///DatePicker.prototype.measure


    /**
     * Create a viewset object based on navigation.
     */
    DatePicker.prototype.viewset = function (type, dateObject/*, options*/) {
        return this.create([dateObject.year, dateObject.month, 1])
    }


    /**
     * Validate a date as enabled and shift if needed.
     */
    DatePicker.prototype.validate = function (type, dateObject, options) {

        var calendar = this,

            // Keep a reference to the original date.
            originalDateObject = dateObject,

            // Make sure we have an interval.
            interval = options && options.interval ? options.interval : 1,

            // Check if the calendar enabled dates are inverted.
            isFlippedBase = calendar.item.enable === -1,

            // Check if we have any enabled dates after/before now.
            hasEnabledBeforeTarget, hasEnabledAfterTarget,

            // The min & max limits.
            minLimitObject = calendar.item.min,
            maxLimitObject = calendar.item.max,

            // Check if we’ve reached the limit during shifting.
            reachedMin, reachedMax,

            // Check if the calendar is inverted and at least one weekday is enabled.
            hasEnabledWeekdays = isFlippedBase && calendar.item.disable.filter(function (value) {

                // If there’s a date, check where it is relative to the target.
                if ($.isArray(value)) {
                    var dateTime = calendar.create(value).pick
                    if (dateTime < dateObject.pick) hasEnabledBeforeTarget = true
                    else if (dateTime > dateObject.pick) hasEnabledAfterTarget = true
                }

                // Return only integers for enabled weekdays.
                return _.isInteger(value)
            }).length/*,

        safety = 100*/



        // Cases to validate for:
        // [1] Not inverted and date disabled.
        // [2] Inverted and some dates enabled.
        // [3] Not inverted and out of range.
        //
        // Cases to **not** validate for:
        // • Navigating months.
        // • Not inverted and date enabled.
        // • Inverted and all dates disabled.
        // • ..and anything else.
        if (!options || (!options.nav && !options.defaultValue)) if (
            /* 1 */ (!isFlippedBase && calendar.disabled(dateObject)) ||
            /* 2 */ (isFlippedBase && calendar.disabled(dateObject) && (hasEnabledWeekdays || hasEnabledBeforeTarget || hasEnabledAfterTarget)) ||
            /* 3 */ (!isFlippedBase && (dateObject.pick <= minLimitObject.pick || dateObject.pick >= maxLimitObject.pick))
        ) {


            // When inverted, flip the direction if there aren’t any enabled weekdays
            // and there are no enabled dates in the direction of the interval.
            if (isFlippedBase && !hasEnabledWeekdays && ((!hasEnabledAfterTarget && interval > 0) || (!hasEnabledBeforeTarget && interval < 0))) {
                interval *= -1
            }


            // Keep looping until we reach an enabled date.
            while ( /*safety &&*/ calendar.disabled(dateObject)) {

                /*safety -= 1
                if ( !safety ) {
                    throw 'Fell into an infinite loop while validating ' + dateObject.obj + '.'
                }*/


                // If we’ve looped into the next/prev month with a large interval, return to the original date and flatten the interval.
                if (Math.abs(interval) > 1 && (dateObject.month < originalDateObject.month || dateObject.month > originalDateObject.month)) {
                    dateObject = originalDateObject
                    interval = interval > 0 ? 1 : -1
                }


                // If we’ve reached the min/max limit, reverse the direction, flatten the interval and set it to the limit.
                if (dateObject.pick <= minLimitObject.pick) {
                    reachedMin = true
                    interval = 1
                    dateObject = calendar.create([
                        minLimitObject.year,
                        minLimitObject.month,
                        minLimitObject.date + (dateObject.pick === minLimitObject.pick ? 0 : -1)
                    ])
                }
                else if (dateObject.pick >= maxLimitObject.pick) {
                    reachedMax = true
                    interval = -1
                    dateObject = calendar.create([
                        maxLimitObject.year,
                        maxLimitObject.month,
                        maxLimitObject.date + (dateObject.pick === maxLimitObject.pick ? 0 : 1)
                    ])
                }


                // If we’ve reached both limits, just break out of the loop.
                if (reachedMin && reachedMax) {
                    break
                }


                // Finally, create the shifted date using the interval and keep looping.
                dateObject = calendar.create([dateObject.year, dateObject.month, dateObject.date + interval])
            }

        } //endif


        // Return the date object settled on.
        return dateObject
    } //DatePicker.prototype.validate


    /**
     * Check if a date is disabled.
     */
    DatePicker.prototype.disabled = function (dateToVerify) {

        var
            calendar = this,

            // Filter through the disabled dates to check if this is one.
            isDisabledMatch = calendar.item.disable.filter(function (dateToDisable) {

                // If the date is a number, match the weekday with 0index and `firstDay` check.
                if (_.isInteger(dateToDisable)) {
                    return dateToVerify.day === (calendar.settings.firstDay ? dateToDisable : dateToDisable - 1) % 7
                }

                // If it’s an array or a native JS date, create and match the exact date.
                if ($.isArray(dateToDisable) || _.isDate(dateToDisable)) {
                    return dateToVerify.pick === calendar.create(dateToDisable).pick
                }

                // If it’s an object, match a date within the “from” and “to” range.
                if ($.isPlainObject(dateToDisable)) {
                    return calendar.withinRange(dateToDisable, dateToVerify)
                }
            })

        // If this date matches a disabled date, confirm it’s not inverted.
        isDisabledMatch = isDisabledMatch.length && !isDisabledMatch.filter(function (dateToDisable) {
            return $.isArray(dateToDisable) && dateToDisable[3] == 'inverted' ||
                $.isPlainObject(dateToDisable) && dateToDisable.inverted
        }).length

        // Check the calendar “enabled” flag and respectively flip the
        // disabled state. Then also check if it’s beyond the min/max limits.
        return calendar.item.enable === -1 ? !isDisabledMatch : isDisabledMatch ||
            dateToVerify.pick < calendar.item.min.pick ||
            dateToVerify.pick > calendar.item.max.pick

    } //DatePicker.prototype.disabled


    /**
     * Parse a string into a usable type.
     */
    DatePicker.prototype.parse = function (type, value, options) {

        var calendar = this,
            parsingObject = {}

        // If it’s already parsed, we’re good.
        if (!value || typeof value != 'string') {
            return value
        }

        // We need a `.format` to parse the value with.
        if (!(options && options.format)) {
            options = options || {}
            options.format = calendar.settings.format
        }

        // Convert the format into an array and then map through it.
        calendar.formats.toArray(options.format).map(function (label) {

            var
                // Grab the formatting label.
                formattingLabel = calendar.formats[label],

                // The format length is from the formatting label function or the
                // label length without the escaping exclamation (!) mark.
                formatLength = formattingLabel ? _.trigger(formattingLabel, calendar, [value, parsingObject]) : label.replace(/^!/, '').length

            // If there's a format label, split the value up to the format length.
            // Then add it to the parsing object with appropriate label.
            if (formattingLabel) {
                parsingObject[label] = value.substr(0, formatLength)
            }

            // Update the value as the substring from format length to end.
            value = value.substr(formatLength)
        })

        // Compensate for month 0index.
        return [
            parsingObject.yyyy || parsingObject.yy,
            +(parsingObject.mm || parsingObject.m) - 1,
            parsingObject.dd || parsingObject.d
        ]
    } //DatePicker.prototype.parse


    /**
     * Various formats to display the object in.
     */
    DatePicker.prototype.formats = (function () {

        // Return the length of the first word in a collection.
        function getWordLengthFromCollection(string, collection, dateObject) {

            // Grab the first word from the string.
            // Regex pattern from http://stackoverflow.com/q/150033
            var word = string.match(/[^\x00-\x7F]+|\w+/)[0]

            // If there's no month index, add it to the date object
            if (!dateObject.mm && !dateObject.m) {
                dateObject.m = collection.indexOf(word) + 1
            }

            // Return the length of the word.
            return word.length
        }

        // Get the length of the first word in a string.
        function getFirstWordLength(string) {
            return string.match(/\w+/)[0].length
        }

        return {

            d: function (string, dateObject) {

                // If there's string, then get the digits length.
                // Otherwise return the selected date.
                return string ? _.digits(string) : dateObject.date
            },
            dd: function (string, dateObject) {

                // If there's a string, then the length is always 2.
                // Otherwise return the selected date with a leading zero.
                return string ? 2 : _.lead(dateObject.date)
            },
            ddd: function (string, dateObject) {

                // If there's a string, then get the length of the first word.
                // Otherwise return the short selected weekday.
                return string ? getFirstWordLength(string) : this.settings.weekdaysShort[dateObject.day]
            },
            dddd: function (string, dateObject) {

                // If there's a string, then get the length of the first word.
                // Otherwise return the full selected weekday.
                return string ? getFirstWordLength(string) : this.settings.weekdaysFull[dateObject.day]
            },
            m: function (string, dateObject) {

                // If there's a string, then get the length of the digits
                // Otherwise return the selected month with 0index compensation.
                return string ? _.digits(string) : dateObject.month + 1
            },
            mm: function (string, dateObject) {

                // If there's a string, then the length is always 2.
                // Otherwise return the selected month with 0index and leading zero.
                return string ? 2 : _.lead(dateObject.month + 1)
            },
            mmm: function (string, dateObject) {

                var collection = this.settings.monthsShort

                // If there's a string, get length of the relevant month from the short
                // months collection. Otherwise return the selected month from that collection.
                return string ? getWordLengthFromCollection(string, collection, dateObject) : collection[dateObject.month]
            },
            mmmm: function (string, dateObject) {

                var collection = this.settings.monthsFull

                // If there's a string, get length of the relevant month from the full
                // months collection. Otherwise return the selected month from that collection.
                return string ? getWordLengthFromCollection(string, collection, dateObject) : collection[dateObject.month]
            },
            yy: function (string, dateObject) {

                // If there's a string, then the length is always 2.
                // Otherwise return the selected year by slicing out the first 2 digits.
                return string ? 2 : ('' + dateObject.year).slice(2)
            },
            yyyy: function (string, dateObject) {

                // If there's a string, then the length is always 4.
                // Otherwise return the selected year.
                return string ? 4 : dateObject.year
            },

            // Create an array by splitting the formatting string passed.
            toArray: function (formatString) { return formatString.split(/(d{1,4}|m{1,4}|y{4}|yy|!.)/g) },

            // Format an object into a string using the formatting options.
            toString: function (formatString, itemObject) {
                var calendar = this
                return calendar.formats.toArray(formatString).map(function (label) {
                    return _.trigger(calendar.formats[label], calendar, [0, itemObject]) || label.replace(/^!/, '')
                }).join('')
            }
        }
    })() //DatePicker.prototype.formats




    /**
     * Check if two date units are the exact.
     */
    DatePicker.prototype.isDateExact = function (one, two) {

        var calendar = this

        // When we’re working with weekdays, do a direct comparison.
        if (
            (_.isInteger(one) && _.isInteger(two)) ||
            (typeof one == 'boolean' && typeof two == 'boolean')
         ) {
            return one === two
        }

        // When we’re working with date representations, compare the “pick” value.
        if (
            (_.isDate(one) || $.isArray(one)) &&
            (_.isDate(two) || $.isArray(two))
        ) {
            return calendar.create(one).pick === calendar.create(two).pick
        }

        // When we’re working with range objects, compare the “from” and “to”.
        if ($.isPlainObject(one) && $.isPlainObject(two)) {
            return calendar.isDateExact(one.from, two.from) && calendar.isDateExact(one.to, two.to)
        }

        return false
    }


    /**
     * Check if two date units overlap.
     */
    DatePicker.prototype.isDateOverlap = function (one, two) {

        var calendar = this,
            firstDay = calendar.settings.firstDay ? 1 : 0

        // When we’re working with a weekday index, compare the days.
        if (_.isInteger(one) && (_.isDate(two) || $.isArray(two))) {
            one = one % 7 + firstDay
            return one === calendar.create(two).day + 1
        }
        if (_.isInteger(two) && (_.isDate(one) || $.isArray(one))) {
            two = two % 7 + firstDay
            return two === calendar.create(one).day + 1
        }

        // When we’re working with range objects, check if the ranges overlap.
        if ($.isPlainObject(one) && $.isPlainObject(two)) {
            return calendar.overlapRanges(one, two)
        }

        return false
    }


    /**
     * Flip the “enabled” state.
     */
    DatePicker.prototype.flipEnable = function (val) {
        var itemObject = this.item
        itemObject.enable = val || (itemObject.enable == -1 ? 1 : -1)
    }


    /**
     * Mark a collection of dates as “disabled”.
     */
    DatePicker.prototype.deactivate = function (type, datesToDisable) {

        var calendar = this,
            disabledItems = calendar.item.disable.slice(0)


        // If we’re flipping, that’s all we need to do.
        if (datesToDisable == 'flip') {
            calendar.flipEnable()
        }

        else if (datesToDisable === false) {
            calendar.flipEnable(1)
            disabledItems = []
        }

        else if (datesToDisable === true) {
            calendar.flipEnable(-1)
            disabledItems = []
        }

            // Otherwise go through the dates to disable.
        else {

            datesToDisable.map(function (unitToDisable) {

                var matchFound

                // When we have disabled items, check for matches.
                // If something is matched, immediately break out.
                for (var index = 0; index < disabledItems.length; index += 1) {
                    if (calendar.isDateExact(unitToDisable, disabledItems[index])) {
                        matchFound = true
                        break
                    }
                }

                // If nothing was found, add the validated unit to the collection.
                if (!matchFound) {
                    if (
                        _.isInteger(unitToDisable) ||
                        _.isDate(unitToDisable) ||
                        $.isArray(unitToDisable) ||
                        ($.isPlainObject(unitToDisable) && unitToDisable.from && unitToDisable.to)
                    ) {
                        disabledItems.push(unitToDisable)
                    }
                }
            })
        }

        // Return the updated collection.
        return disabledItems
    } //DatePicker.prototype.deactivate


    /**
     * Mark a collection of dates as “enabled”.
     */
    DatePicker.prototype.activate = function (type, datesToEnable) {

        var calendar = this,
            disabledItems = calendar.item.disable,
            disabledItemsCount = disabledItems.length

        // If we’re flipping, that’s all we need to do.
        if (datesToEnable == 'flip') {
            calendar.flipEnable()
        }

        else if (datesToEnable === true) {
            calendar.flipEnable(1)
            disabledItems = []
        }

        else if (datesToEnable === false) {
            calendar.flipEnable(-1)
            disabledItems = []
        }

            // Otherwise go through the disabled dates.
        else {

            datesToEnable.map(function (unitToEnable) {

                var matchFound,
                    disabledUnit,
                    index,
                    isExactRange

                // Go through the disabled items and try to find a match.
                for (index = 0; index < disabledItemsCount; index += 1) {

                    disabledUnit = disabledItems[index]

                    // When an exact match is found, remove it from the collection.
                    if (calendar.isDateExact(disabledUnit, unitToEnable)) {
                        matchFound = disabledItems[index] = null
                        isExactRange = true
                        break
                    }

                        // When an overlapped match is found, add the “inverted” state to it.
                    else if (calendar.isDateOverlap(disabledUnit, unitToEnable)) {
                        if ($.isPlainObject(unitToEnable)) {
                            unitToEnable.inverted = true
                            matchFound = unitToEnable
                        }
                        else if ($.isArray(unitToEnable)) {
                            matchFound = unitToEnable
                            if (!matchFound[3]) matchFound.push('inverted')
                        }
                        else if (_.isDate(unitToEnable)) {
                            matchFound = [unitToEnable.getFullYear(), unitToEnable.getMonth(), unitToEnable.getDate(), 'inverted']
                        }
                        break
                    }
                }

                // If a match was found, remove a previous duplicate entry.
                if (matchFound) for (index = 0; index < disabledItemsCount; index += 1) {
                    if (calendar.isDateExact(disabledItems[index], unitToEnable)) {
                        disabledItems[index] = null
                        break
                    }
                }

                // In the event that we’re dealing with an exact range of dates,
                // make sure there are no “inverted” dates because of it.
                if (isExactRange) for (index = 0; index < disabledItemsCount; index += 1) {
                    if (calendar.isDateOverlap(disabledItems[index], unitToEnable)) {
                        disabledItems[index] = null
                        break
                    }
                }

                // If something is still matched, add it into the collection.
                if (matchFound) {
                    disabledItems.push(matchFound)
                }
            })
        }

        // Return the updated collection.
        return disabledItems.filter(function (val) { return val != null })
    } //DatePicker.prototype.activate


    /**
     * Create a string for the nodes in the picker.
     */
    DatePicker.prototype.nodes = function (isOpen) {

        var
            calendar = this,
            settings = calendar.settings,
            calendarItem = calendar.item,
            nowObject = calendarItem.now,
            selectedObject = calendarItem.select,
            highlightedObject = calendarItem.highlight,
            viewsetObject = calendarItem.view,
            disabledCollection = calendarItem.disable,
            minLimitObject = calendarItem.min,
            maxLimitObject = calendarItem.max,


            // Create the calendar table head using a copy of weekday labels collection.
            // * We do a copy so we don't mutate the original array.
            tableHead = (function (collection, fullCollection) {

                // If the first day should be Monday, move Sunday to the end.
                if (settings.firstDay) {
                    collection.push(collection.shift())
                    fullCollection.push(fullCollection.shift())
                }

                // Create and return the table head group.
                return _.node(
                    'thead',
                    _.node(
                        'tr',
                        _.group({
                            min: 0,
                            max: DAYS_IN_WEEK - 1,
                            i: 1,
                            node: 'th',
                            item: function (counter) {
                                return [
                                    collection[counter],
                                    settings.klass.weekdays,
                                    'scope=col title="' + fullCollection[counter] + '"'
                                ]
                            }
                        })
                    )
                ) //endreturn

                // Materialize modified
            })((settings.showWeekdaysFull ? settings.weekdaysFull : settings.weekdaysLetter).slice(0), settings.weekdaysFull.slice(0)), //tableHead


            // Create the nav for next/prev month.
            createMonthNav = function (next) {

                // Otherwise, return the created month tag.
                return _.node(
                    'div',
                    ' ',
                    settings.klass['nav' + (next ? 'Next' : 'Prev')] + (

                        // If the focused month is outside the range, disabled the button.
                        (next && viewsetObject.year >= maxLimitObject.year && viewsetObject.month >= maxLimitObject.month) ||
                        (!next && viewsetObject.year <= minLimitObject.year && viewsetObject.month <= minLimitObject.month) ?
                        ' ' + settings.klass.navDisabled : ''
                    ),
                    'data-nav=' + (next || -1) + ' ' +
                    _.ariaAttr({
                        role: 'button',
                        controls: calendar.$node[0].id + '_table'
                    }) + ' ' +
                    'title="' + (next ? settings.labelMonthNext : settings.labelMonthPrev) + '"'
                ) //endreturn
            }, //createMonthNav


            // Create the month label.
            //Materialize modified
            createMonthLabel = function (override) {

                var monthsCollection = settings.showMonthsShort ? settings.monthsShort : settings.monthsFull

                // Materialize modified
                if (override == "short_months") {
                    monthsCollection = settings.monthsShort;
                }

                // If there are months to select, add a dropdown menu.
                if (settings.selectMonths && override == undefined) {

                    return _.node('select',
                        _.group({
                            min: 0,
                            max: 11,
                            i: 1,
                            node: 'option',
                            item: function (loopedMonth) {

                                return [

                                    // The looped month and no classes.
                                    monthsCollection[loopedMonth], 0,

                                    // Set the value and selected index.
                                    'value=' + loopedMonth +
                                    (viewsetObject.month == loopedMonth ? ' selected' : '') +
                                    (
                                        (
                                            (viewsetObject.year == minLimitObject.year && loopedMonth < minLimitObject.month) ||
                                            (viewsetObject.year == maxLimitObject.year && loopedMonth > maxLimitObject.month)
                                        ) ?
                                        ' disabled' : ''
                                    )
                                ]
                            }
                        }),
                        settings.klass.selectMonth + ' browser-default',
                        (isOpen ? '' : 'disabled') + ' ' +
                        _.ariaAttr({ controls: calendar.$node[0].id + '_table' }) + ' ' +
                        'title="' + settings.labelMonthSelect + '"'
                    )
                }

                // Materialize modified
                if (override == "short_months")
                    if (selectedObject != null)
                        return _.node('div', monthsCollection[selectedObject.month]);
                    else return _.node('div', monthsCollection[viewsetObject.month]);

                // If there's a need for a month selector
                return _.node('div', monthsCollection[viewsetObject.month], settings.klass.month)
            }, //createMonthLabel


            // Create the year label.
            // Materialize modified
            createYearLabel = function (override) {

                var focusedYear = viewsetObject.year,

                // If years selector is set to a literal "true", set it to 5. Otherwise
                // divide in half to get half before and half after focused year.
                numberYears = settings.selectYears === true ? 5 : ~~(settings.selectYears / 2)

                // If there are years to select, add a dropdown menu.
                if (numberYears) {

                    var
                        minYear = minLimitObject.year,
                        maxYear = maxLimitObject.year,
                        lowestYear = focusedYear - numberYears,
                        highestYear = focusedYear + numberYears

                    // If the min year is greater than the lowest year, increase the highest year
                    // by the difference and set the lowest year to the min year.
                    if (minYear > lowestYear) {
                        highestYear += minYear - lowestYear
                        lowestYear = minYear
                    }

                    // If the max year is less than the highest year, decrease the lowest year
                    // by the lower of the two: available and needed years. Then set the
                    // highest year to the max year.
                    if (maxYear < highestYear) {

                        var availableYears = lowestYear - minYear,
                            neededYears = highestYear - maxYear

                        lowestYear -= availableYears > neededYears ? neededYears : availableYears
                        highestYear = maxYear
                    }

                    if (settings.selectYears && override == undefined) {
                        return _.node('select',
                            _.group({
                                min: lowestYear,
                                max: highestYear,
                                i: 1,
                                node: 'option',
                                item: function (loopedYear) {
                                    return [

                                        // The looped year and no classes.
                                        loopedYear, 0,

                                        // Set the value and selected index.
                                        'value=' + loopedYear + (focusedYear == loopedYear ? ' selected' : '')
                                    ]
                                }
                            }),
                            settings.klass.selectYear + ' browser-default',
                            (isOpen ? '' : 'disabled') + ' ' + _.ariaAttr({ controls: calendar.$node[0].id + '_table' }) + ' ' +
                            'title="' + settings.labelYearSelect + '"'
                        )
                    }
                }

                // Materialize modified
                if (override == "raw")
                    return _.node('div', focusedYear)

                // Otherwise just return the year focused
                return _.node('div', focusedYear, settings.klass.year)
            } //createYearLabel


        // Materialize modified
        createDayLabel = function () {
            if (selectedObject != null)
                return _.node('div', selectedObject.date)
            else return _.node('div', nowObject.date)
        }
        createWeekdayLabel = function () {
            var display_day;

            if (selectedObject != null)
                display_day = selectedObject.day;
            else
                display_day = nowObject.day;
            var weekday = settings.weekdaysFull[display_day]
            return weekday
        }


        // Create and return the entire calendar.
        return _.node(
                // Date presentation View
                'div',
                    _.node(
                        'div',
                        createWeekdayLabel(),
                        "picker__weekday-display"
                    ) +
                    _.node(
                        // Div for short Month
                        'div',
                        createMonthLabel("short_months"),
                        settings.klass.month_display
                    ) +
                    _.node(
                        // Div for Day
                        'div',
                        createDayLabel(),
                        settings.klass.day_display
                    ) +
                    _.node(
                        // Div for Year
                        'div',
                        createYearLabel("raw"),
                        settings.klass.year_display
                    ),
                settings.klass.date_display
            ) +
            // Calendar container
            _.node('div',
                _.node('div',
                (settings.selectYears ? createMonthLabel() + createYearLabel() : createMonthLabel() + createYearLabel()) +
                createMonthNav() + createMonthNav(1),
                settings.klass.header
            ) + _.node(
                'table',
                tableHead +
                _.node(
                    'tbody',
                    _.group({
                        min: 0,
                        max: WEEKS_IN_CALENDAR - 1,
                        i: 1,
                        node: 'tr',
                        item: function (rowCounter) {

                            // If Monday is the first day and the month starts on Sunday, shift the date back a week.
                            var shiftDateBy = settings.firstDay && calendar.create([viewsetObject.year, viewsetObject.month, 1]).day === 0 ? -7 : 0

                            return [
                                _.group({
                                    min: DAYS_IN_WEEK * rowCounter - viewsetObject.day + shiftDateBy + 1, // Add 1 for weekday 0index
                                    max: function () {
                                        return this.min + DAYS_IN_WEEK - 1
                                    },
                                    i: 1,
                                    node: 'td',
                                    item: function (targetDate) {

                                        // Convert the time date from a relative date to a target date.
                                        targetDate = calendar.create([viewsetObject.year, viewsetObject.month, targetDate + (settings.firstDay ? 1 : 0)])

                                        var isSelected = selectedObject && selectedObject.pick == targetDate.pick,
                                            isHighlighted = highlightedObject && highlightedObject.pick == targetDate.pick,
                                            isDisabled = disabledCollection && calendar.disabled(targetDate) || targetDate.pick < minLimitObject.pick || targetDate.pick > maxLimitObject.pick,
                                            formattedDate = _.trigger(calendar.formats.toString, calendar, [settings.format, targetDate])

                                        return [
                                            _.node(
                                                'div',
                                                targetDate.date,
                                                (function (klasses) {

                                                    // Add the `infocus` or `outfocus` classes based on month in view.
                                                    klasses.push(viewsetObject.month == targetDate.month ? settings.klass.infocus : settings.klass.outfocus)

                                                    // Add the `today` class if needed.
                                                    if (nowObject.pick == targetDate.pick) {
                                                        klasses.push(settings.klass.now)
                                                    }

                                                    // Add the `selected` class if something's selected and the time matches.
                                                    if (isSelected) {
                                                        klasses.push(settings.klass.selected)
                                                    }

                                                    // Add the `highlighted` class if something's highlighted and the time matches.
                                                    if (isHighlighted) {
                                                        klasses.push(settings.klass.highlighted)
                                                    }

                                                    // Add the `disabled` class if something's disabled and the object matches.
                                                    if (isDisabled) {
                                                        klasses.push(settings.klass.disabled)
                                                    }

                                                    return klasses.join(' ')
                                                })([settings.klass.day]),
                                                'data-pick=' + targetDate.pick + ' ' + _.ariaAttr({
                                                    role: 'gridcell',
                                                    label: formattedDate,
                                                    selected: isSelected && calendar.$node.val() === formattedDate ? true : null,
                                                    activedescendant: isHighlighted ? true : null,
                                                    disabled: isDisabled ? true : null
                                                })
                                            ),
                                            '',
                                            _.ariaAttr({ role: 'presentation' })
                                        ] //endreturn
                                    }
                                })
                            ] //endreturn
                        }
                    })
                ),
                settings.klass.table,
                'id="' + calendar.$node[0].id + '_table' + '" ' + _.ariaAttr({
                    role: 'grid',
                    controls: calendar.$node[0].id,
                    readonly: true
                })
            )
            , settings.klass.calendar_container) // end calendar

             +

            // * For Firefox forms to submit, make sure to set the buttons’ `type` attributes as “button”.
            _.node(
                'div',
                _.node('button', settings.today, "btn-flat picker__today",
                    'type=button data-pick=' + nowObject.pick +
                    (isOpen && !calendar.disabled(nowObject) ? '' : ' disabled') + ' ' +
                    _.ariaAttr({ controls: calendar.$node[0].id })) +
                _.node('button', settings.clear, "btn-flat picker__clear",
                    'type=button data-clear=1' +
                    (isOpen ? '' : ' disabled') + ' ' +
                    _.ariaAttr({ controls: calendar.$node[0].id })) +
                _.node('button', settings.close, "btn-flat picker__close",
                    'type=button data-close=true ' +
                    (isOpen ? '' : ' disabled') + ' ' +
                    _.ariaAttr({ controls: calendar.$node[0].id })),
                settings.klass.footer
            ) //endreturn
    } //DatePicker.prototype.nodes



    /**
     * The date picker defaults.
     */
    DatePicker.defaults = (function (prefix) {

        return {

            // The title label to use for the month nav buttons
            labelMonthNext: '下个月',
            labelMonthPrev: '上个月',

            // The title label to use for the dropdown selectors
            labelMonthSelect: '选择月',
            labelYearSelect: '选择年',

            // Months and weekdays
            monthsFull: ['一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月'],
            monthsShort: ['一', '二', '三', '四', '五', '六', '七', '八', '九', '十', '十一', '十二'],
            weekdaysFull: ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'],
            weekdaysShort: ['日', '一', '二', '三', '四', '五', '六'],

            // Materialize modified
            weekdaysLetter: ['S', 'M', 'T', 'W', 'T', 'F', 'S'],

            // Today and clear
            today: '今天',
            clear: '清空',
            close: '关闭',

            // The format to show on the `input` element
            format: 'yyyy-mm-dd',
            container: 'body',
            // Classes
            klass: {

                table: prefix + 'table',

                header: prefix + 'header',

                // Materialize Added klasses
                date_display: prefix + 'date-display',
                day_display: prefix + 'day-display',
                month_display: prefix + 'month-display',
                year_display: prefix + 'year-display',
                calendar_container: prefix + 'calendar-container',
                // end

                navPrev: prefix + 'nav--prev',
                navNext: prefix + 'nav--next',
                navDisabled: prefix + 'nav--disabled',

                month: prefix + 'month',
                year: prefix + 'year',

                selectMonth: prefix + 'select--month',
                selectYear: prefix + 'select--year',

                weekdays: prefix + 'weekday',

                day: prefix + 'day',
                disabled: prefix + 'day--disabled',
                selected: prefix + 'day--selected',
                highlighted: prefix + 'day--highlighted',
                now: prefix + 'day--today',
                infocus: prefix + 'day--infocus',
                outfocus: prefix + 'day--outfocus',

                footer: prefix + 'footer',

                buttonClear: prefix + 'button--clear',
                buttonToday: prefix + 'button--today',
                buttonClose: prefix + 'button--close'
            }
        }
    })(Picker.klasses().picker + '__')

    /**
     * Extend the picker to add the date picker.
     */
    Picker.extend('pickadate', DatePicker)
});



